4 nub vs 3 nub mopar steel wheels question

[Darter6]

I have a set of 2, 14'' steel wheels from a disc brake 73 Duster BBP. They have 4 nubs to hold the dog dish on. The other 2 wheels are 15's from a 88 Dodge Diplomat have 3 nubs.It seems that my dog dish caps from 64 Valiant will fit the 3 nub just fine but I can't seem to get them on the 4 nub wheels. I already damaged one trying to wack it on.Anybody run into this before?:banghead:

 

[jas0162]

I have ran into this before. I think I figured out the 3 nub wheels were from a ferd.